soriano was wasted leadoff that's for sure... seniority, whatever else at play makes it ~normal i bet. ie i'm not knocking the choice from a broad perpsective of RL realities of the MLB, but it was a bad choice nonetheless. power is objectively wasted leadoff, and it's way less prevalent than a leadoff hitter.
simple break-even analysis of whether they give more value scoring runs or raking them in. would be relative to team and spot in order etc etc (this info is readily available to teams). as far as a simple easy to consume theory, you won't find one. it's too open ended and relies too much on human speculation about ability. a team full of vets is more easily predicted than kids.
the soriano situation may be "hindsight" in nature. he was young then,eh? you don't knwo what they are going to do ahead of time even with a healthy track record. you simply estimate their ability with the info at-hand.
i don't think anyone was putting soriano behind giambi in 2002. i just don't have a good enough memory and didn't click that link
(boo-hiss yankees, red sox, dodgers, cubs.. pretentious lil teams)
giambi is a suitable leadoff play, but his power makes him more useful eslewhere.
power with more PA/AB is great, but what's in front of him? the 3 worst hitters on the team and a backup catcher 1/3rd of the games. if they are future hoF, maybe it's a good idea? even then i bet it would be ~close at best.
don't think of it as 1-9, it's 1-X (27+ repeating pattern)... starting at 1 is key only for initial order. best players near front (without getting into who goes where in the front). the loss of ab moving obp guys from "1" to "9" outweighs the benefit of giambi getting 60 more AB with no one on base leading off.
i said that oddly, but you get the idea, placing 1 or 2 players or starting at "7,8,9" instead of "1" with your "best" players is a net negative. power with no one on for 1 ab 100% every game is a bad thing. very difficult to overcome the mathematical repercussions.
let's say 1/3 of the time somoene will be on base and he averages "4" ab for easy math. 25% fewer runners on instances from batting leadoff. it's more complicated than that obviously, but you can see the weight it carries and imagine the rest.
it'll be higher due to the other factors too (more than 1 player in front of the guy will matter) and then a reduciton because i didn't consider % change a non leadoff hitter leads off an inning etc.... but 1 full PA guaranteed every game is heavy.